crypto: caam - fix MDHA key derivation for certain user key lengths

Fuzz testing uncovered an issue when |user key| > |derived key|.
Derived key generation has to be fixed in two cases:

1. Era >= 6 (DKP is available)
DKP cannot be used with immediate input key if |user key| > |derived key|,
since the resulting descriptor (after DKP execution) would be invalid -
having a few bytes from user key left in descriptor buffer
as incorrect opcodes.

Fix DKP usage both in standalone hmac and in authenc algorithms.
For authenc the logic is simplified, by always storing both virtual
and dma key addresses.

2. Era < 6
The same case (|user key| > |derived key|) fails when DKP
is not available.
Make sure gen_split_key() dma maps max(|user key|, |derived key|),
since this is an in-place (bidirectional) operation.

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Reviewed-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 47 insertions, 20 deletions

diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
index 63a86b6b8b96..bd01bcd799e8 100644
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -199,6 +199,18 @@ static int aead_set_sh_desc(struct crypto_aead *aead)
 				ctx->cdata.keylen - CTR_RFC3686_NONCE_SIZE);
 	}
 
+	/*
+	 * In case |user key| > |derived key|, using DKP<imm,imm> would result
+	 * in invalid opcodes (last bytes of user key) in the resulting
+	 * descriptor. Use DKP<ptr,imm> instead => both virtual and dma key
+	 * addresses are needed.
+	 */
+	ctx->adata.key_virt = ctx->key;
+	ctx->adata.key_dma = ctx->key_dma;
+
+	ctx->cdata.key_virt = ctx->key + ctx->adata.keylen_pad;
+	ctx->cdata.key_dma = ctx->key_dma + ctx->adata.keylen_pad;
+
 	data_len[0] = ctx->adata.keylen_pad;
 	data_len[1] = ctx->cdata.keylen;
 
@@ -210,16 +222,6 @@ static int aead_set_sh_desc(struct crypto_aead *aead)
 			      ARRAY_SIZE(data_len)) < 0)
 		return -EINVAL;
 
-	if (inl_mask & 1)
-		ctx->adata.key_virt = ctx->key;
-	else
-		ctx->adata.key_dma = ctx->key_dma;
-
-	if (inl_mask & 2)
-		ctx->cdata.key_virt = ctx->key + ctx->adata.keylen_pad;
-	else
-		ctx->cdata.key_dma = ctx->key_dma + ctx->adata.keylen_pad;
-
 	ctx->adata.key_inline = !!(inl_mask & 1);
 	ctx->cdata.key_inline = !!(inl_mask & 2);
 
@@ -248,16 +250,6 @@ static int aead_set_sh_desc(struct crypto_aead *aead)
 			      ARRAY_SIZE(data_len)) < 0)
 		return -EINVAL;
 
-	if (inl_mask & 1)
-		ctx->adata.key_virt = ctx->key;
-	else
-		ctx->adata.key_dma = ctx->key_dma;
-
-	if (inl_mask & 2)
-		ctx->cdata.key_virt = ctx->key + ctx->adata.keylen_pad;
-	else
-		ctx->cdata.key_dma = ctx->key_dma + ctx->adata.keylen_pad;
-
 	ctx->adata.key_inline = !!(inl_mask & 1);
 	ctx->cdata.key_inline = !!(inl_mask & 2);
 
@@ -2999,6 +2991,7 @@ enum hash_optype {
 /**
  * caam_hash_ctx - ahash per-session context
  * @flc: Flow Contexts array
+ * @key: authentication key
  * @flc_dma: I/O virtual addresses of the Flow Contexts
  * @dev: dpseci device
  * @ctx_len: size of Context Register
@@ -3006,6 +2999,7 @@ enum hash_optype {
  */
 struct caam_hash_ctx {
 	struct caam_flc flc[HASH_NUM_OP];
+	u8 key[CAAM_MAX_HASH_BLOCK_SIZE] ____cacheline_aligned;
 	dma_addr_t flc_dma[HASH_NUM_OP];
 	struct device *dev;
 	int ctx_len;
@@ -3306,6 +3300,19 @@ static int ahash_setkey(struct crypto_ahash *ahash, const u8 *key,
 	ctx->adata.key_virt = key;
 	ctx->adata.key_inline = true;
 
+	/*
+	 * In case |user key| > |derived key|, using DKP<imm,imm> would result
+	 * in invalid opcodes (last bytes of user key) in the resulting
+	 * descriptor. Use DKP<ptr,imm> instead => both virtual and dma key
+	 * addresses are needed.
+	 */
+	if (keylen > ctx->adata.keylen_pad) {
+		memcpy(ctx->key, key, keylen);
+		dma_sync_single_for_device(ctx->dev, ctx->adata.key_dma,
+					   ctx->adata.keylen_pad,
+					   DMA_TO_DEVICE);
+	}
+
 	ret = ahash_set_sh_desc(ahash);
 	kfree(hashed_key);
 	return ret;
@@ -4536,11 +4543,27 @@ static int caam_hash_cra_init(struct crypto_tfm *tfm)
 
 	ctx->dev = caam_hash->dev;
 
+	if (alg->setkey) {
+		ctx->adata.key_dma = dma_map_single_attrs(ctx->dev, ctx->key,
+							  ARRAY_SIZE(ctx->key),
+							  DMA_TO_DEVICE,
+							  DMA_ATTR_SKIP_CPU_SYNC);
+		if (dma_mapping_error(ctx->dev, ctx->adata.key_dma)) {
+			dev_err(ctx->dev, "unable to map key\n");
+			return -ENOMEM;
+		}
+	}
+
 	dma_addr = dma_map_single_attrs(ctx->dev, ctx->flc, sizeof(ctx->flc),
 					DMA_BIDIRECTIONAL,
 					DMA_ATTR_SKIP_CPU_SYNC);
 	if (dma_mapping_error(ctx->dev, dma_addr)) {
 		dev_err(ctx->dev, "unable to map shared descriptors\n");
+		if (ctx->adata.key_dma)
+			dma_unmap_single_attrs(ctx->dev, ctx->adata.key_dma,
+					       ARRAY_SIZE(ctx->key),
+					       DMA_TO_DEVICE,
+					       DMA_ATTR_SKIP_CPU_SYNC);
 		return -ENOMEM;
 	}
 
@@ -4566,6 +4589,10 @@ static void caam_hash_cra_exit(struct crypto_tfm *tfm)
 
 	dma_unmap_single_attrs(ctx->dev, ctx->flc_dma[0], sizeof(ctx->flc),
 			       DMA_BIDIRECTIONAL, DMA_ATTR_SKIP_CPU_SYNC);
+	if (ctx->adata.key_dma)
+		dma_unmap_single_attrs(ctx->dev, ctx->adata.key_dma,
+				       ARRAY_SIZE(ctx->key), DMA_TO_DEVICE,
+				       DMA_ATTR_SKIP_CPU_SYNC);
 }
 
 static struct caam_hash_alg *caam_hash_alloc(struct device *dev,